The invention relates to plating feeders for use in circular knitting machines and in particular knitting machines having arrangements for exchanging feeders during knitting.
Plating may be effected by feeding a pair of individual yarns with one yarn having a lead over the other at a plating angle. The plating angle is critical and requires the yarns to be fed along converging paths from the feeder. Separate mouths are provided on plating feeders for each of the yarns which are spaced from one another.
Feeders on knitting machines may be exchanged during knitting. This involves moving the feeder, trapping and cutting the yarn to separate the last part of the knitted yarn from the feeder, when taking a feeder out of action. When inserting a feeder, the exchange involves laying the yarn between the active needles or licking the new yarn into the hooks of the needles by means of latches.
When applying plating feeders to machines having facilities for exchanging feeders, the requirement for separate and spaced feeder mouths conflicts with the need for precise location of the last part of the knitting yarn for trapping and cutting and of the new yarn for initially feeding it to the needles. In double cylinder machines the problem is more acute as feeder movement up or down is restricted by the cylinders and the only free movement used in exchanging feeders is in a direction tangential to the cylinders.
Another problem arises when plating during reciprocation of a circular machine. In that case the plating angle must be reversed when reversing the direction of knitting so as to maintain the yarns in proper relationship. Whatever the application of a plating feeder, it should also be capable of adjusting the plating angle to adapt it to different requirements. The adjustment is often critical and requires great skill.
It is an object of the invention to provide a plating feeder or a method of control of such a feeder which enables it to be exchanged for another feeder.
It is a further object to provide a plating feeder suitable for use in reciprocatory plating and which is easily adjustable.
It is also an object to provide such plating feeders which may be used on double cylinder machines.